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54 Cards in this Set
- Front
- Back
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What are the expected levels of TSH & thyroid hormone in primary hyperthyroidism?
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high thyroid hormone w/low TSH
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How do you assess pitiutary function?
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give a sugar loading test; sugar should decrease cortisol levels if it's healthy
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Where are the components of the adrenal glands derived from?
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cortex=mesoderm
medulla=neural crest |
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What controls the zona fasciculata?
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renin-angiotensin system
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What does the zona fasciculata secrete?
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aldosterone
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What controls the zona fasciculata?
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ACTH, CRH (hypothalamus)
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What does the zona fasciculta secrete?
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cortisol, sex hormones
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What controls the zona reticularis?
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ACH, CRH (hypothalamus)
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What does the zona reticularis secrete?
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sex hormones
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What controls the medulla?
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preganglionic sympathetic fibers
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What does the medulla secrete?
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catecholamines (Epi, NE)
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What is a pheochromocytoma?
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medullary adrenal tumor that causes episodic hypertension
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Do the R/L adrenal glands differ in how they drain?
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yes; L= L adrenal vein-> L renal vein*-> IVC (R gland doesn't have R renal vein)
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What is a neurohypophysis?
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the posterior pituitary
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What is an adenohypophysis?
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the anterior pituitary
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What does the posterior pitiutary secrete?
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vassopressin & oxytocin (NOTE: these are MADE in the hypothalamus but SECRETED by the posterior pituitary)
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What does the anterior pituitary secrete?
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FSH, LH, ACTH,TSH, prolactin, GH
think "FLAT PiG" |
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What is an alpha subunit?
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common piece to TSH, LH, FSH, & hCG
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What is the beta subunit?
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determines hormone specificity
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What does prolactin do?
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it increases dopamine synthesis/secretion from the hypothalmus (increased dopamine-> prolactin inhibition); thus a dopamine agonist are used to tx hyperprolactemia; it inhibits GnRH in females
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What increases prolactin production?
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TRH
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What increases TSH production?
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TRH
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What increases ACTH production?
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CRH
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What increases FSH & LH production?
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GnRH
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What increases GH production?
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GHRH
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What does somatostatin inhibit?
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TSH & GH
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How is aldosterone synthesized?
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ACTH + cholesterol (via desmolase or circulating)+ 33-hydroxysteriod dehydrogenase
->progesterone-> 11-deoxycorticosterone -> corticosterone + aldosterone synthase ->aldosterone |
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How is cortisol synthesized?
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17-hydroxypregnenolone (from pregnenolone) -> 17 alpha-hydroxyprogesterone (from progesterone) -> 11-deoxycortisol (from 11-deoxycorticosterone) -> cortisol
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How is DHEA synthesized?
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from 17-hydroxypregnenolone
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How is testosterone synthesized?
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DHEA -> androstendione (from 17 alpha-hydroxyprogesterone) -> testosterone (reduced to DHT)
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how is estrone synthesized?
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from androstenedione
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how is estradiol synthesized?
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from testosterone
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what happens w/a 17 alpha-hydroxylase deficiency?
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low sex hormones, low cortisol, high mineralocorticoids; hypertension, hypokalemia, phenotypically female w/o maturation
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what happens w/a 21 beta-hydroxylase deficiency?
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low cortisol, low mineralocorticoids, high sex hormones, high ACTH; hypotension, hyponatremia, hyperkalemia, volume depletion, masculinization of females
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what happens w/11 beta-hydroxylase deficiency?
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low cortisol, low aldosterone, increased sex hormones, hypertension, masculinization of females
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What makes parathyriod hormone?
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chief cells of the parathyroids.
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What does parathyroid hormone do?
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increases bone resorption of Ca & P, increases kidney reabsorption of Ca, decreases kidney reabsorption of P, increases vitamin D production.
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What motivates parathyroid hormone?
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decreased serum Ca.
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What's the significance of increasing vitamin D production?
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vitamin D increases absorption of Ca & P by the intestines & increases bone resorption of Ca & P.
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What is the active form of vitamin D?
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vitamins D3 & D2 are turned into 25-OH by the liver & then to the active form of 1,25-(OH)2 by the kidney.
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How does hyperparathyroidism affect Ca, P, & alk phos levels?
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elevates Ca, lowers P, & elevates alk phos.
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How does Paget's disease affect alk phos?
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majorly increases it.
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How does renal insufficiency affect Ca & P?
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decreases Ca, elevates P.
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Where does calcitonin come from?
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parafollicular cells of the thyroid (C-cells).
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What does calcitonin do?
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it decreases bone resorption of(opposes PTH). BOTH PTH & calcitonin are stimulated by increase in serum Ca.
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Name the steroid/thyroid hormones.
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think "PET CAT"; progesterone, estrogen, testosterone, cortisol, aldosterone, thyroxine & T3
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Where do thyroid hormones come from?
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T4 & some T3 come from follicles (most of T3 is formed in the blood).
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What does T3 do?
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brain maturation, bone growth, beta-adrenergic effects, increase BMR. think "4 B's"
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What regulates thyroid hormone secretion?
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TRH (hypothalamus) -> TSH (ant pituitary) -> follicular cells -> T4/T3
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What happens to thyroid binding protein during pregnancy?
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increased production -> decrease free hormone; estrogen increases TBG
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Which tissues are dependent on insulin for glucose absorption?
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skeletal mm & adipose tissue.
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Where does cortisol come from?
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adrenal gland; zona fasciculata.
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What does cortisol do?
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anti-inflammatory, increases metabolism, suppresses immune fx & bone formation.
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How is cortisol regulated?
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CRH (hypothalamus)-> ATCH (ant pituitary) -> adrenal fasiculata -> cortisol.
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